Renewable shoe for airplane-skids.



E. C. HALL.

REMOVABLE SHOE FOR AIRPLANE SKIDS.

APPLICATION FILED ocT. 20. 1911.

LQWMM Patented May 28, 1918.

RENEWABLE SHOE FOB. AIRPLANE-SKIES.

To all whom it may concern;

Be it known that r, ERNEST o. HALL, a citizen of the United States, residing at Warren, in the county of Trumbull and State of Ohio, have invented certain new.

and useful Improvements in Renewable Shoes for Airplane-Skids, of which the following is a specification, reference being had therein to the accompanying drawing.

This invention relates to renewable shoesthe ground with a reat deal of force and is, consequently, Sub ected to a great deal of wear. For this reason it has been customary to reinforce the end of the skid with a suitable fitting and to provide this fitting with a wearin surface, but even when the fitting is provi ed with the wearing surface this surface will wear away rapidly and. it is necessary to renew the fitting at more or less frequent intervals. Inasmuch as the bolt and screw holes of the new fitting do not always register with the holes in the skid it is frequently necessary to form new holes with the result that the skid is weakened so that the whole structure must be renewed. Both the skid and its'fitting are of an expensive construction and a renewal of these parts constitutes a very considerable item in the cost of upkeep of the machine.

The object of the present invention is to provide a detachable shoe for a skid of this kind which can be readily renewed when worn. To this end it is a further object of this invention to provide suitable attachin devices which will secure the shoe to the ski in a very edective manner, and which can be manipulated to very quickly and easily remove a worn shoe and replace the same with a new shoe. A further object of the invention is to so mount the shoe on the skid that its contact surface will form a continuation of the lower edge of the skid and will not project therefrom in such amanner as to catch upon obstructions.

.In theaccompanying drawings Figure 1 is a side elevation of a portion of the tail of ble,

Specification of Letters Patent. Pat erning-d1 Maw 2 any, Application filed. October 20, 1917. I

Serial No. 197,531.

- skid, partly broken away and showing another arrangement of the shoe.

In these drawings I have illustrated certam embodiments of my invention and have shown the same as applied to a skid of ordinary construction forming part of an airplane of standard construction, but it will be understood that the invention is applicaeither with or without modification, to skids of variouskinds, which may be used with airplanes of any type.

The skid, which is shown at 1, is usually of wood and is. connected at its upper end with the tail 2 of the airplane. The connecting devices are arranged within the tail, andinasmuch as they form no part of thepresent invention it is not necessary to illustrate or describe them. The skid extends downwardly and rearwardly, and is slightly curved at its lower portion. The wooden skid is ordinarily provided with a protecting fitting of sheet metal, as shown at 3, this fitting comprising a strip of metal bent about the lower end of the skid and having its edge portions bent to form flanges extending along the sides of the skid. Preferably the lower end of the fitting is bent into a hook shape to receive the end of the skid and the front end of the fitting is provided with ears 4 to receive a bolt 5, by means of which it is secured to the skid. In the form shown in Fig. 2 the wearing plate or shoe is secured to the skid by means of the fitting, but obviously the fitting could be omitted so far as the present invention is concerned. The shoe, which is shown at 6, is preferably made of cast iron, or other similar material and has its upper surface curved to conform substantially to the curvature of the lOWer portion of the skid. The lower, or ground engaging, surface of the shoe is also curved but on a shorter radius than the upper surface thereof so that the shoe has its reatest thickness at approximately its longltudinal center, and tapers toward its ends. The shoe is detachably secured to the skid by suitable attaching means, which preferably comprise IWI cooperating clamping members. In the present construction these clamping members comprise a part 7 rigidly secured to theportion flared away from the adjacent surface of the fitting. This outwardly flared portion is provided with inwardly extending flanges 8 which are brazed or otherwise secured to the edges of the fitting, thus forming between the fitting and the body portion and flanges of the part 7 a socket into which the tapered end of the shoe may extend. Cooperating with the socket member is a clamping member, which is here shown as a plate 9, having a portion overlapping that edge of the shoe 6 opposite the edge which is in engagement with the socket 7 and which is secured to the skid by means of a bolt 10. In that form of the device here shown the bolt does not extend through the body of the shoe, but the shoe is provided with a notch 11 to embrace the bolt and hold the shoe against lateral displacement. If desired, the plate 9 may also be provided with projections 12 to overlap the lateral edges of the shoe and further resist any tendency to lateral movement. In the presentconstruetion I have shown both the notch in the end of the shoe and the projections on the clamping plate, but it may be understood that either or both may be used. The bolt may be, and preferably is, rigidly secured to the clamping plate 9, which thus forms the head of the bolt. The bolt extends upwardly through the fitting 3 on the lower side of the skid, through the skid and through the end of the fitting on the upper side of the skid, thus serving as a fastening device for the fitting, and also serving to arrange the bolt end and nut in a position where they are readily accessible. By arranging the bolt at the end of the shoe and notching the end of the shoe to receive the same the shoes are more readily fitted to the skids because the same exactness of registration is not required between the notch and the bolt hole in the skid as is required between the bolt hole in the skid and a hole in the shoe, but it will be understood, of

course, that the opening in the shoe may, if

desired, be in the form of a bolt hole instead of a notch, and that in such-instances the shape of the head or clamping plate of the bolt will be modified accordingly.

It will be obvious that the attaching de- .vices may take various forms without departing from the spirit of my invention and in Fig. 4 I have shown a slightly modified new of the invention, in which the shoe 13 has outwardly extending projections, or ribs, 1 1 along the upper lateral edges thereof, which ribs are adapted to enter channels, or recesses, 15 formed in clamping plates 16 arranged at the sides of the skid 1 and secured thereto by a clamping bolt 17. In this construction no fitting is shown on the skid although it will be apparent that, if desired, the fitting could be interposed between the shoe and the skid.

In Fig. 5 I have illustrated a further development of the invention in which the shoe forms an extension to the skid and has its upwardly extending contact surface arranged substantially in alinement with the lower end of the skid, thus providing a substantially smooth, straight surface for the skid down to the point of contact between the shoe and the ground. This construction eliminates the projection or hump formed by the shoe when mounted on the skid as shown in Fig. 2. In that form of the device shown in Fig. 5 the skid 1 and the fitting 3 are substantially the same as those above described, but the extreme lower end of the skid and its fitting have been given aslightly different shape. The shoe itself, which is shown at 18, is of a slightly different shape from that shown in Fig. 2. Its upper surfaceis curved to conform with the curvature at the lower end of the skid, and the lower or contact surface of the skid has been given an irregular curvature so that while the shoe tapers toward its opposite ends it has its greatest thickness near the rear end thereof. The rear end of the shoe is curved about a comparatively short axis so that when fitted to the skid it will cooperate therewith to form a rounded end portion. The forward portion of the contact surface of the shoe is arranged in substantial alinement with the lower edge of the skid and forms a continuation of that edge of the skid. Consequently the shoe as a whole is arranged in substantial alinement with and forms a continuation of the skid. The shoe may be secured to the skid in any suitable manner, but preferably cooperating clamping devices are provided for this purpose and in the present construction I have employed clamping devices quite similar to those shown in connection with Fig. 2, but have reversed the positions of the two devices so that the fixed socket receives the forwardly extending part of the shoe and the movable clamping member engages the lower rear end of the shoe. The skid shown in Fig. 5 is provided with a fitting and I have, therefore, shown the clamping devices as applied to the fitting. but it will be obvious that if desired the fitting could be eliminated. As shown in this figure a socket member 19 is secured to the fitting at a point slightly in the clamping member into firm engagement becomes too large for eer/sea ranged to form a socket to receive the upper forward end of the shoe. This socket member is preferably secured to the skid by mean of a screw 20 and by brazing the upwardly extending side members, or flanges, 21 of the socket to the fitting. The rear end of the shoe is engaged by a clamping member 22 which is provided with a shoulder 23 to engage the lip or tapered end portion 24 of the shoe. The clamping member is also provided with side members, as shown by dotted lines at 25, which overlap the end of the shoe and hold the same against lateral displacement. 'Ihis clamping member may be secured to the skid in any suitable manner but in the present construction I have extended a bolt 26 through the end portion-of the fitting and through the clamping member, to which it is secured by means of a nut 27 which serves to draw with the shoe and the fitting. Preferably the fitting is reinforced by brazing a plate of metal 28 to that portion thereof through which the bolt extends. In order to center the clamping member and properly position the same with relation to the fitting and theshoe prefer to form a recess, or socket, 29 in that portion of the fitting which underlies the upper end of the clamp ing member and provide the clamping member with a projection 30 adapted to enter the recess. Ihis arrangement of clamping devices serves to secure the shoe very firmly to the skid, and the adjustable clamping member is so arranged that it is readily accessible for manipulation when the shoe is to be renewed. Further, this manner of attaching the shoe to the skid avoids the necessity of boring the skid, which not only weakens the skid but because of the wear on the wood about the bolt the hole eventually the bolt and does not hold the same firmly.

While I have shown and described one embodiment of my invention I Wishit to he understood that I do not desire to be limited to t e details of construction as various modifi ations will occur to a person skilled in the art.

Having now fully described my invention, what I claim as new and desire to-secure by Letters Patent, is

I. In an airplane, the combination with a skid and a fitting therefor, of a wearing plate separate from said fitting, and means for detachably securing said wearing plate or flanges,

tit

skid, of a shoe separate from said skid, and a device secured to said skid and having a socket to receive one edge of said shoe, and a clamping device to engage another edge of said shoe.

-4:.'II1 an airplane, the combination with a skid, of a shoe separate from said skid, and cooperating clamping devices comprising a socket and a coiiperating part to respec- 'tively engage difierent parts of said shoe to secure the same to said skid.

5. In an airplane, the combination with a skid, of a shoe separate from said skid, and a device secured to said skid and having a socket to receive one edge of said shoe, a clamping member to engage another edge of said shoe, and a bolt to operate said clamping member and secure the same to said skid.

6. In an airplane, the combination with a skid, of a shoe separate from said skid, a device secured to said skid and having a socket to receive one edge of said shoe, a clamping member arranged near the opposite edge of said shoe and having parts overlapping the lateral edges of said shoe, and means for securing said clamping member to said skid.

7. In an airplane, the combination with a skid, and a fitting mounted on the lower end of said skid, of a part secured to said fitting to form a socket, a shoe having one edge extending into said socket, a clamping device comprising an attaching member extending through said fitting and arranged to engage said shoe at a point remote from 100 said socket and tohold said shoe in engagement with said socket.

8. In an airplane, the combination with a skid, of clamping members mounted on said skid and spaced apart, ashoe arranged lot between said clamping members and having parts extending into engagement therewith, and means for causing said clamping members to grip said shoe.

9.In an ai lane, the combination with 1110 a skid, of clamping members moilnted on said skid, spaced apart and having recesses therein, a shoe mounted between said clamping members and having parts extending into the recesses in respective clamping 115 members, and means for causing said clamping members to grip said shoe.

10. In an airplane, the combination with a skid, of a shoe separate from said skid, having a thickened portion and shaped to 120 fit upon the end portion of said skid, and means for detachably securing said shoe to said skid in substantially longitudinal alinement therewith.

II. In an airplane, the combination with 1 a skid, of a shoe separate from-said skid, having its forward end tapered and arranged with its contact surface'in substantially longitudinal alinement with the lower edge of said skid, and having its rear end 30 &

terminating adjacent to the rear end of said skid and having its thickest portion near the rear end thereof, and means for detachably securing said shoe to said skid.

I 12. In an airplane, the combination with a skid having its lower edge curved upwardly at the rear end thereof, of a shoe mounted in engagement with said upwardly curved portion of said skid and of gradually increasing thickness from its forward end to its rear end, and means for securing said shoe to said skid.

13. In an airplane, the combination with a skid, of a shoe separate from said skid, a socket member secured to the under side of said skid to receive the forward end of said shoe, and a clamping member mounted on the rear end of said skid and having a part adapted to engage the rear end of said shoe,

and means for clamping said member in engagement with said shoe.

14. In an airplane, the combination with a skid, of a shoe separate from said skid,

a socket member secured to the under side of said skid to receive the forward end of said shoe, and a clamping member mounted on the rear end of said skid and having a part adapted to engage the rear end of said shoe, and a bolt secured to the rear end of said skid and extending through said clamping member, and having a nut to engage said clamping member.

15. In an airplane, the combination with a skid, and a fitting mounted on the lower end of said skid, of a part secured to said fitting along the under side of said skid to form a socket, a bolt extending through said fitting at the rear end thereof, a clamping member mounted on said bolt, and a shoe having one edge adapted to enter said socket and having its other edge arranged to be engaged by said clamping member.

In testimony whereof, I afiix my signature hereto.

ERNEST C. HALL. 

